How to Safely Remove a Flash Drive From a Mac
Yanking flash drives out of a computer, or otherwise removing them improperly, is one of the main causes of damage to flash drives. The flash drive is turned on and processing information when it is suddenly powered off in the middle of its work; this causes problems with the flash drive that may make it transfer files at slower speeds or result in other errors. Safely removing the flash drive in a Mac is simple and ensures you avoid such errors.
Click the flash drive icon, which is located on the desktop.
Press the "Eject" button on your Mac keyboard and wait for the flash drive icon to flash once and then disappear from the toolbar. When this happens, the flash drive has been deactivated.
Remove the flash drive from the port once the icon disappears.